sub2cli desktop 0.2.0

Unsigned macOS desktop DMG.\n\nHighlights:\n- Dark cyberpunk desktop GUI aligned to the selected v2 visual direction.\n- Multi-relay and multi-account management.\n- Endpoint ping, batch group tests, health check, dry-run inject preview, and rollback backup.\n- README refreshed with screenshots and Gatekeeper bypass instructions.\n\nInstall note:\nxattr -dr com.apple.quarantine /Applications/sub2cli.app if macOS blocks the unsigned app.